So the function is given by . (I changed the variable back to y to match with your problem. It's a "dummy" variable and can be anything we wish.)

How about domain and range? Well, the domain of f is so this is the range of . The allowed domain of is . This domain gives the exact range as we expect (it must give a range at least as large as the expected range, else we need to modify the domain such that it will.) So the function may be expressed as: